Margaret (2011)

Bothersome New York City high-school student Lisa Cohen (17), who consistently messes up her life and that of boy classmates, searches New York in vain for a fit cowboy hat to wear at an excursion with her separated father and stepmother. Spotting one on bus driver Maretti's head but failing to board, she stubbornly runs along and keeps claiming his confused attention, until the bus hits a blind senior, who is wounded fatally The NYPD quickly closes the case as an accident, but Lisa, duly consumed by guilt and spared any charge, starts bothering everyone and making a mean pest of herself, not only at home, as self-absorbed actress mother may deserve, but also in the precinct, tracking down the victim's uninterested kin out of town and even Maretti at home. A family friend lawyer gets involved in the case, digging in to compromising circumstances and causing real trouble to people who were of the hook.